VXLAN (virtual extensible LAN) is a virtualization technology was developed to address the scalability problems associated with large cloud computing systems. VXLAN provides mechanisms to aggregate and tunnel multiple layer 2 Ethernet sub-networks across a layer 3 infrastructure. For example, VXLAN may be used to connect two or more layer 2 network domains and make them look like a common layer 2 domain. This allows virtual machines on different networks to communicate as if they were in the same layer 2 subnet. Technically, VXLAN uses a VLAN-like encapsulation technique to encapsulate MAC-based OSI layer 2 Ethernet frames within layer 3 UDP packets. VXLAN endpoints, which terminate VXLAN tunnels and may be both virtual or physical switch ports, are known as VXLAN tunnel endpoints (VTEPs). Networking devices generally process VXLAN traffic transparently. That is, IP encapsulated traffic is switched or routed the same as any IP traffic. The VXLAN gateways (VTEPs) provide the encapsulating/de-encapsulating services central to VXLAN. VTEPS can be virtual bridges in the hypervisor, VXLAN aware VM applications or VXLAN capable switching hardware.
The VXLAN specification was developed by Arista, Broadcom, Intel, VMware, and others to improve scaling in virtualized data centers, among other applications. Routers and switches made by Broadcom are thus ubiquitous in VXLAN systems. In such networks, egress port to next hop mapping (EGR_PORT_TO_NHI_MAPPING) is one-to-one for every egress port, and hence only one next hop index can be mapped to an egress port. In a virtual link trunking (VLT) topology, when network port is a VLT lag (link aggregation), VLT peers will be in the same broadcast LAN and it is not possible to reach multiple remote VTEPs from a VLT peer through inter-chassis link (ICL), due to a particular restriction imposed or associated with Broadcom routers. This limitation causes certain bottleneck conditions that can greatly reduce network performance. In an embodiment, ICL is a link standard that provides a dedicated blade for switch ports for end devices in a network fabric by transporting traffic between chassis over dedicated high-speed links.
One such affect is traffic tromboning where traffic between a branch user and an Internet-based site may be backhauled over a corporate WAN, through a data center, then “tromboned” through to its Internet destination, then back to that data center, and finally is sent back over the corporate WAN to the original site. Such tromboning effects can add significant amounts of latency (e.g., plus 30 to 80 milliseconds of access latency for branch users) that can greatly effect network performance.
It is advantageous, therefore, to facilitate multiple tunnels to be reachable via ICL from VLT peers and also to avoid traffic tromboning with optimal path to all next hops.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.